The present disclosure relates to systems and methods for treating subterranean formations.
Natural resources such as oil or gas residing in a subterranean formation can be recovered by drilling a wellbore that penetrates the formation. The wellbore passes through a variety of subterranean formations. This may include non-reservoir zones (i.e., formations that do not contain oil and gas) and reservoir zones (i.e., formations that do contain oil or gas). The subterranean formations may also have varying degrees of permeability. During the drilling of the wellbore, a drilling fluid may be used to, among other things, cool the drill bit, lubricate the rotating drill string to prevent it from sticking to the walls of the wellbore, prevent blowouts by serving as a hydrostatic head to the entrance into the wellbore of formation fluids, and remove drill cuttings from the wellbore. A drilling fluid may be circulated downwardly through a drill pipe and drill bit and then upwardly through the wellbore to the surface.
When the drilling fluid contacts permeable subterranean formations, fluid (e.g., water or oil) may be lost into the formation. A drilling operation where this has occurs may also be said to have “fluid loss.” Fluid loss control additives may be included in the drilling fluid to reduce fluid loss into the formation. Fluid loss and lost circulation can be more significant during drilling operations into high-permeability zones (e.g., unconsolidated zones or depleted formations), vugular zones, and fractures (e.g., either pre-existing fractures or fractures created during the subterranean operation). When the permeability of the formation is high, for example, because of unconsolidated formations or microfractures, the rate of fluid loss may increase to the point where the drilling fluid can no longer be circulated back to the surface as efficiently, or at all.
While embodiments of this disclosure have been depicted, such embodiments do not imply a limitation on the disclosure, and no such limitation should be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.